• Korean Journal of Poultry Science
• /
• v.41 no.1
• /
• pp.69-75
• /
• 2014

This study was carried out to investigate the performance of laying period of A and B strains of Korean native ducks (KND). One hundred sixty eight ducks were used in this work and divided into A and B strains (6 replications/strain, 14 birds/replication). Ducks were fed with laying ducks' feedstuff (CP 15%, ME 2,900 kcal/kg) for the age of 20~80 wk old. There was no significant difference on body weight, feed intake and egg weight between A and B strains. Weekly body wt of KNDs was the lowest at the age of 40~48 wk old, and that of those was high at the age of 24~32 wk and 64~80 wk old (P<0.05). Weekly feed intake significantly decreased at the age of 36~48 wk and 68~72 wk old (P<0.05), but there was no significant difference at the age of 52~56 wk old. Weekly egg wt was the lowest at the age of 32~40 wk old. Egg production ratio of B strain was higher compared to that of A strain at the age of 24~28 wk, 60~64 wk and 20~80 wk old. Weekly egg production ratio was the highest at the age of 28~32 wk old, and was high maintained until the age of 48 wk old. However, weekly egg production ratio decreased from the age of 52 wk old to the age of 68 wk old. Number of egg of B strain (267.5) was higher than that of A strain (235.6) at the age of 20~80 wk old. There was no significant difference on feed conversion ratio between A and B strain at the age of 28~36 wk old, but feed conversion ratio of A strain was higher than that of B strain at the other weeks (P<0.05). These results provided the basic data on the record of laying period of Korean native ducks.

• Journal of agricultural medicine and community health
• /
• v.31 no.1
• /
• pp.9-20
• /
• 2006

Objectives: This study was aimed at investigating the ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis and related factors. And we want to compare the ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis and related factors among the provinces. Methods: In order to compare, the data was referred to National health insurance center for affirming the insurance type of the dead. And age adjusted mortality rate of tuberculosis of each insurance type was analyzed by whole country and the provinces. Related factors of the provinces were gathered from public statistic books. We analysed correlation study between the ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis and related factors among the provinces. Results: Major findings were as follows 1. The ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis was 5.6. And the ratio was relatively high at 40-60 ages. 2. The ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis by the province was varying. And the factors that were financial independence, crowdedness, percent of people on medical aid, population size served by each public health center, number of hospital by a million peoples have correlated with increment of the ratio. Conclusions: As a consequence of tuberculosis control, the ratio was high. Thus this finding suggests that medical utilization and preventive behavior, environment of tuberculosis patient are under handicapped condition. Especially large cities like metropolitan area who have high financial independence, high population density, high percentage of medical aid peoples have high ratio of medical aid over health insurance of age adjusted mortality rate of tuberculosis. There is need for additional and systematic research on the attitude or tendency toward medical services(inc1uding preventive services) utilization of medical aid tuberculosis patients.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.12
• /
• pp.1757-1762
• /
• 2011

Aflatoxins are natural contaminants of poultry feeds and feed ingredients and cause liver damage, immunosuppression, reduction in performance and mortality in broilers. A number of studies have been carried out to study the effects of aflatoxin on feed conversion ratio in broilers. The results on feed conversion ratio of 10 research articles in broilers fed with aflatoxin from first day of age to six weeks of age were compiled and were subjected to meta-analysis. Chi-square test and $Tau^2$ (heterogeneity co-efficient) were applied to test for significance of heterogeneity of studies. To integrate results, fixed effect model by Inverse Variance method (IV method) was used when heterogeneity was insignificant and otherwise random effect model by DerSimonian and Laird Method (DL method) was used. The results of meta-analysis showed that the adverse effect of aflatoxin on feed conversion ratio at the end of first week was negligible, second week was medium and third to six weeks was very large.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.11a
• /
• pp.1135-1140
• /
• 2001

The purpose of this study is to investigate the shrinkage properties of high strength concrete according to the S/A ratio at early age. The main parameters are as follows : S/A ratio is 30, 35, 38, 41, 45%, W/B ratio 24.9%, SF/B ratio 8%. FA/B 15%. The size of specimen is l0$\times$10$\times$40cm and the shrinkage is measured by the embedded gage at each end of the specimens. From the test, it was found that the slump-flow of concrete was high, and also autogenous shrinkage increased and drying shrinkage decreased as S/A ratio increased.

• Phonetics and Speech Sciences
• /
• v.3 no.1
• /
• pp.117-123
• /
• 2011

Most individuals with hearing impairment have difficulty in understanding speech in noisy situations. This study was conducted to investigate sentence recognition ability using the Korean Standard-Sentence Lists for Preschoolers (KS-SL-P2) in pre-school age children with cochlear implants and hearing aids. The subjects of this study were 10 pre-school age children with hearing aids, 12 pre-school age children with cochlear implants, and 10 pre-school age children with normal hearing. Three kinds of signal-to-noise (SNR) conditions (+10 dB, +5 dB, 0 dB) were applied. The results for all pre-school age children with cochlear implants and hearing aids presented a significant increase in the score for sentence recognition as SNR increased. The sentence recognition score in speech noise were obtained with the SNR +10 dB. Significant differences existed between groups in terms of their sentence recognition ability, with the cochlear implant group performing better than the hearing aid group. These findings suggest the presence of a sentence recognition test using speech noise is useful for evaluating pre-school age children's listening skill.

• Korean journal of food and cookery science
• /
• v.17 no.5
• /
• pp.441-455
• /
• 2001

Korean food habits, dietary behaviors and perception of food were compared according to gender and age. The subjects were composed of 274 males and 315 females. According to age, the age group of 10s was 26.3%, 20s 24.6%, 30s 16.8%, 40s 18.7%, and 50s and over 13.6%, respectively. The majority (65.2%) of all age groups except the 20s took meals 3 times a day and the ratio 20s eating twice a day was higher than other age groups. All age groups took cooked rice(bap) two or three times a day and the 20s group took smaller amount than other age groups did. The younger age groups of 10s and 20s took larger amount of processed food. The older age groups appeared to have higher frequency of eating fish, bean, vegetable, Kimchi, laver.brown seaweed, soybean oil, sesame oil, coffee, tea, and rice cake(ddhuk). The younger groups have the higher frequency of eating ramyeon, corn flake, milk, milk-processed food, butterㆍmargarine, ham.sausage, carbonated drink candyㆍchocolate, hamburger, and pizza. All age groups perceived cooked rice(bap), meat, fish, egg, vegetable, fruit, and Kimchi to be the delicious, excellent and healthy food. According to the above results, age groups of 30s and over had relatively better food habits compared with those of younger groups. On the other hand, the groups of 10s and 20s had meals irregularly, showed a high ratio of skipping meals, and took processed food much. These results raised a concern of their nutritional imbalance in the future. Therefore, the correct nutritional education must be conducted to make these age groups have a healthy food habits.

• Communications of Mathematical Education
• /
• v.28 no.2
• /
• pp.281-302
• /
• 2014

The purpose of this paper is to offer a history of golden ratio, the criterion raised by Markowsky, and misconceptions about golden ratio. Markowsky(1992) insists that the golden ratio does not appear in the great pyramid of Khufu. On the contrary, we claim that there exists the golden ration on it. Elementary and middle school text books, and domestic history books deal with the great pyramid of Khuff and the Parthenon by examples of the golden ratio. Text books make many incorrect statements about golden ratio; so in teaching and learning the golden ratio, we recommend the design-composition of dynamic symmetry, for example, industrial design, aerodynamic, architecture design, and screen design. Finally we discuss the axial age how to affect the school mathematics with respect to the subject of Thales and the golden ratio.

• The Journal of the Korean life insurance medical association
• /
• v.3 no.1
• /
• pp.219-232
• /
• 1986

A study on establishment of normal range of cardiothoracic ratio calculated from photofluorography film of chest by age and sex in a total of the 6,598 insureds was undertaken. The results were as follows: 1. In male group, the frequency distribution of cardiothoracic ratio was skewed weakly to the right in second decade, symmetrical in third and fourth decade, and was skewed weakly to the left in fifth and sixth decade; in female group, it was skewed weakly to the left in second, third and fourth decade, and was skewed weakly to the right in fifth and sixth decade. 2. On assumption that normal range of cardiothoracic ratio should comprise about 85% of all cardiothoracic ratios in each age group of both sexes, the sites of deviation from mean value of cardiothoracic ratio corresponding to maximum and minimum cardiothoracic ratio in the range of about 85% above mentioned were detected by statistical method on the frequency distribution of log tranformed cardiothoracic ratio, and $M{\pm}1.3$ sindicating normal range of cardiothoracic ratio was determined. In male group, normal range of cardiothoracic ratio determined by statistical method is 35-45%, 40-50%, 40-50%, 40-50% and 40-50% succesively in order from second to sixth decade; in female group, 40-50%, 40-50%, 40-50%, 45-55% and 45-55%.

• Imaging Science in Dentistry
• /
• v.49 no.1
• /
• pp.19-26
• /
• 2019

Purpose: It has been proposed that using new prediction methods, such as neural networks based on dental data, could improve age estimation. This study aimed to assess the possibility of exploiting neural networks for estimating age by means of the pulp-to-tooth ratio in canines as a non-destructive, non-expensive, and accurate method. In addition, the predictive performance of neural networks was compared with that of a linear regression model. Materials and Methods: Three hundred subjects whose age ranged from 14 to 60 years and were well distributed among various age groups were included in the study. Two statistical software programs, SPSS 21 (IBM Corp., Armonk, NY, USA) and R, were used for statistical analyses. Results: The results indicated that the neural network model generally performed better than the regression model for estimation of age with pulp-to-tooth ratio data. The prediction errors of the developed neural network model were acceptable, with a root mean square error (RMSE) of 4.40 years and a mean absolute error (MAE) of 4.12 years for the unseen dataset. The prediction errors of the regression model were higher than those of the neural network, with an RMSE of 10.26 years and a MAE of 8.17 years for the test dataset. Conclusion: The neural network method showed relatively acceptable performance, with an MAE of 4.12 years. The application of neural networks creates new opportunities to obtain more accurate estimations of age in forensic research.

• Clinical and Experimental Pediatrics
• /
• v.51 no.3
• /
• pp.256-261
• /
• 2008

Purpose : Leptin and adiponectin are two representative adipocytokines. Leptin increases, but adiponectin decreases, with obesity and insulin resistance. We aimed to study the relationship between the leptin/adiponectin ratio and insulin resistance in healthy children. Methods : Seventy-seven healthy children (36 boys and 41 girls) were enrolled in this study. Anthropometric measurements were performed, and the percentage of weight for height (%WFH) was calculated in each subject. Fasting plasma levels of glucose, insulin, leptin, adiponectin, testosterone, estradiol, and sex-hormone binding globulin (SHBG) were measured. The free androgen index (FAI) was used as a representative of testosterone bioactivity. The homeostasis model assessment was used to estimate the degree of insulin resistance (HOMA-IR). Results : In the boys, HOMA-IR was significantly correlated with age, pubertal stage, free androgen index (FAI), leptin, and the leptin/adiponectin ratio. HOMA-IR was also significantly related to age, percentage of weight for height (%WFH), pubertal stage, estradiol, leptin, and the leptin/adiponectin ratio in girls. The leptin/adiponectin ratio was independently related to HOMA-IR after adjusting for age, %WFH, and FAI in the boys (P<0.05). The leptin/adiponectin ratio was not independently related to HOMA-IR after adjusting for age, %WFH, and estradiol in girls. Conclusion : In non-obese healthy children, the leptin/adiponectin ratio was significantly correlated with insulin resistance. The leptin/adiponectin ratio was independently related to insulin resistance even after adjusting for age, degree of obesity, and androgen levels in healthy boys.